Computer systems and devices generally receive electrical power through a power supply unit (PSU). A power supply unit includes electronic components such as a power factor circuit and a DC to DC converter to insure proper power supply to all components in a computer system. A power supply unit generally receives power from an external source such as an alternating current source and converts the power to voltage outputs appropriate for powering the various components in a computer system. A power supply unit will often include electronic components to allow distribution of power to the various devices of the computer system. A power supply unit thus will include a capacitor to assist in smoothing out voltage signals to produce an uninterrupted and uniform power supply signal. The capacitor also assists in changing voltage levels output from the power supply unit.
In order for the power supply unit to function correctly, the capacitor should not be charged beyond a capacitance limit. Otherwise, overcharging of the capacitor can affect the performance of the capacitor and thereby prevent the proper operation of the power supply unit. Therefore, measuring the capacitance of the capacitor is necessary to prevent the capacitor from being overcharged and also to determine whether the power supply unit is operating within normal parameters.
Currently, a power supply unit must be shut down in order to measure the capacitance of the capacitor. Such shut downs are inconvenient as the entire system must be powered down to perform the measurement. Measurement of capacitance while the power supply unit is operational is thus currently difficult to achieve because it requires disabling the power supply thereby interrupting device operation.
Thus, there is a need for a power supply unit that allows measurement of capacitance during normal operation of the power supply unit. There is also a need for a power supply unit that can measure the capacitance value and store the data for detection of faults. There is a further need for a power supply unit that measures internal capacitance through either charge or discharge of an internal capacitor.